1. The Cell Cycle & Cell Division

2. The Cell Cycle

3. Animated Cycle

4. MITOSIS

5. Mitosis
The process of cell division which results in the production of two daughter cells from a single parent cell.
The daughter cells are identical to one another and to the original parent cell.

6. Mitosis can be divided into stages
Interphase
Prophase
Metaphase
Anaphase
Telophase & Cytokinesis

7. Interphase The cell prepares for division
Animal Cell
DNA replicated
Organelles replicated
Cell increases in size
Plant Cell
DNA replicated
Organelles replicated
Cell increases in size

8. Interphase Plant Cell Animal Cell
Photographs from:

9. Prophase The cell prepares for nuclear division
Animal Cell
Packages DNA into chromosomes
Plant cell
Packages DNA into chromosomes

10. Prophase Plant Cell Animal Cell
Photographs from:

11. Metaphase The cell prepares chromosomes for division
Animal Cell
Chromosomes line up at the center of the cell
Spindle fibers attach from daughter cells to chromosomes at the centromere
Plant Cell
Chromosomes line up at the center of the cell
Spindle fibers attach from daughter cells to chromosomes at the centromere

12. Metaphase Plant Cell Animal Cell
Photographs from:

13. Anaphase The chromosomes divide
Animal Cell
Spindle fibers pull chromosomes apart
½ of each chromosome (called chromotid) moves to each daughter cell
Plant Cell
Spindle fibers pull chromosomes apart
½ of each chromosome (called chromotid) moves to each daughter cell

14. Anaphase Plant Cell Animal Cell
Photographs from:

15. Telophase The cytoplasm divides
Plant Cell
DNA spreads out
2 nuclei form
New cell wall forms between to nuclei to form the 2 new daughter cells
Animal Cell
DNA spreads out
2 nuclei form
Cell membrane pinches in to form the 2 new daughter cells

16. Telophase Plant Cell Animal Cell
Photographs from:

17. II. The “C” Words in Mitosis
A. Chromatin
1. DNA + protein - found in nucleus of
a non-dividing cell
B. Chromatid
1. one of two identical parts of a
chromosome in a mitotic cell
2. sister chromatids are identical
a. same DNA and the same genes

19. 1. holds sister chromatids together
C. Centromere
1. holds sister chromatids together
2. attaches chromosome to spindle fibers
D. Centrosomes
1. found in plant and animal cells
2. spindle fibers radiate from a pair of
these during mitosis
E. Centrioles
1. found in the centrosomes of animal
cells only
2. one pair in each centrosome

21. REVIEW THE CELL CYCLE
A. Interphase
1.G1- cells grow & mature(time between)
between division and DNA replication)
2.G0 - DNA does not replicate (cell will
not divide)
S – DNA replicates
3.G2 – cell prepares for division if the
DNA does replicate (cell will divide)

22. Cell Cycle

23. The Cell Cycle B. Mitosis 1. Prophase a. chromosomes become visible
b. centrosomes appear, separate and
move toward poles
c. spindle appears
d. nucleolus and nuclear membrane
disappear

24. Interphase Prophase

25. 2. Metaphase
a. chromosomes line up at equator
3. Anaphase
a. centromeres divide
b. sister chromatids separate
1) considered individual chromosomes
c. chromosomes begin to move apart
d. chromosomes move to opposite poles

26. Metaphase Late Anaphase

27. 4. Telophase
a. chromosomes reach the poles
b. spindles disappear
c. nuclear membrane and nucleolus
reappear in each cell
d. chromosomes become less distinct
e. cytokinesis begins

28. Metaphase Interphase Telophase-Cytokinesis

29. C. Cytokinesis
1. a cleavage furrow develops in animal
cells - a cell plate forms in plant cells
2. two distinct daughter cells form
3. daughter cells enter interphase
4. offspring cells have identical copies
of chromosomes and ½ the original
cell cytoplasm and organelles

31. Mitosis Animation

32. mitosis Events during Mitosis
Interphase: Cells may appear inactive during this stage, but they are quite the opposite. This is the longest period of the complete cell cycle during which DNA replicates, the centrioles divide, and proteins are actively produced. For a complete description of the events during Interphase, read about the Cell Cycle.
Prophase: During this first mitotic stage, the nucleolus fades and chromatin (replicated DNA and associated proteins) condenses into chromosomes. Each replicated chromosome comprises two chromatids, both with the same genetic information. Microtubules of the cytoskeleton, responsible for cell shape, motility and attachment to other cells during interphase, disassemble. And the building blocks of these microtubules are used to grow the mitotic spindle from the region of the centrosomes.
Prometaphase: In this stage the nuclear envelope breaks down so there is no longer a recognizable nucleus. Some mitotic spindle fibers elongate from the centrosomes and attach to kinetochores, protein bundles at the centromere region on the chromosomes where sister chromatids are joined. Other spindle fibers elongate but instead of attaching to chromosomes, overlap each other at the cell center.
mitosis

33. mitosis
MITOSIS
Metaphase: Tension applied by the spindle fibers aligns all chromosomes in one plane at the center of the cell.
Anaphase: Spindle fibers shorten, the kinetochores separate, and the chromatids (daughter chromosomes) are pulled apart and begin moving to the cell poles.
Telophase: The daughter chromosomes arrive at the poles and the spindle fibers that have pulled them apart disappear.
Cytokinesis: The spindle fibers not attached to chromosomes begin breaking down until only that portion of overlap is left. It is in this region that a contractile ring cleaves the cell into two daughter cells. Microtubules then reorganize into a new cytoskeleton for the return to interphase.
Cancer cells reproduce relatively quickly in culture. In the Cancer Cell CAM compare the length of time these cells spend in interphase to that for mitosis to occur.

34. Animal Mitosis -- Review
Interphase                                                             
Prophase                                                             
Metaphase                                                             
Anaphase                                                             
Telophase                                                             

35. Plant Mitosis -- Review
Interphase                                                             
Prophase                                                             
Metaphase                                                             
Anaphase                                                             
Telophase